Fifty years later, the lust for closure surrounding JFK's 1963 murder is stronger than ever. New search-for-the-truth books, movies and documentaries keep fanning the flames of speculation.

Here are the top ten theories about what really happened. Which one is true?None of them.

The eleventh theory is that there is no single theory. The Kennedy murder was a combination of many theories described below. #1, #2, #3, #4, #5, #6, #8 and #10. The murder plot involved the Mossad, the CIA, Illuminati Banksters, 2 US Presidents and the Mafia who were all interconnected co-conspirators in the web of deceit.

1. The Federal Reserve Bankster Theory

On June 4, 1963, President Kennedy signed an order that gave authority to the Secretary of the Treasury to issue silver certificates. The order, known as Executive Order 11110, was intended to serve as an interim measure while the government attempted to reduce the amount of silver being used to mint coins. However, conspiracy theories, like those presented in Jim Marrs’ 1989 book Crossfire: The Plot that Killed Kennedy, claim that this order gave power to the Treasury over the Federal Reserve.

According to theorists, the Federal Reserve Bank was safeguarded by a shadowy group of internationalbanksters who resented having their power curtailed. They used their incredible wealth and influence to have Kennedy assassinated.

There are several problems with this theory, the main one is that Executive Order 11110 did not, in fact, create any new authority over the Federal Reserve Bank. It merely transferred already existing authority from the President to the Secretary of the Treasury. Also, Kennedy’s plan was to reduce the use of treasury silver and increase printed Federal Reserve Bank notes – effectively giving the Reserve more power. Still, the idea of an international banking cabal pulling the strings – and having a president eliminated – sounds more exciting.

2. The Lyndon B. Johnson Theory

Lyndon B. Johnson and Deputy Director of the CIA Richard Helms

According to certain theorists, at least two US presidents were involved in the assassination. Suspect #1 - , Lyndon B. Johnson who features in one of the most widely believed conspiracy theories of all. In fact, in 2003, a Gallup poll revealed that 20 percent of Americans thought Johnson had something to do with JFK’s assassination.

Johnson's motive? His desire to become president, his need to cover up scandals, and his involvement with the FBI. Tycoons paid for the assassination so they would be better served by Johnson’s policies.

A new twist to the theory is the alleged emergence and (still) pending release of secret recordings made by President Kennedy’s now deceased widow, Jackie Onassis. According to some claims, the tapes reveal that Jackie thought Lyndon B. Johnson was involved as well.

3. UFO Cover-Up Theory

According to theUFO Cover-Up Theory, President Kennedy was assassinated for showing too much interest in alien activity. The two crucial pieces of ‘evidence’ here are: a letter written by JFK to the CIA demanding to see secret UFO files; and a note from the CIA director that says, “As you must know, Lancer [President Kennedy’s Secret Service code name] has made some inquiries regarding our activities, which we cannot allow.”

“The most important idea that people have not grasped at all is that this program started in early 1942,” says Robert Wood, former Deputy Director of major aerospace manufacturer and defence contractor McDonnell Douglas. “The second most important idea is that the program is not under the control of the President and when the President was about to leak it, they bumped him off.”

4. The Mafia Theory

As JFK conspiracy theories go, this one is not far-fetched. Members of the Mafia did work with the CIA in an attempt to assassinate Fidel Castro. And the Mafia, of course, also had the expertise necessary to dispose of important people. A few researchers have concluded that the infamous crime organization had a hand in the shooting – especially given that Jack Ruby, who shot Lee Harvey Oswald, was known to be acquainted with the Mob.

This particular theory is further complicated by the possible involvement of the CIA and anti-Castro Cubans. The Mob themselves were said to have been anti-Castro because of their lucrative stakes in the casinos Castro shut down. What’s more, the Mafia was mad at JFK’s brother, Bobby, who led a tough campaign against organized crime. In the end, they had the motive and they had the means, but whether pulled the trigger, we may never know.

5. The George Bush Senior Theory

According to this theory, US president, George Bush Senior is alleged to have been part of a conspiracy plot to kill JFK using his connections with the CIA and the Mafia.

Supporters of this hypothesis cite George H. W. Bush’s presence in Dallas on the day Kennedy was assassinated, his long, shadowy involvement with the CIA, and his supposed family ties to organized crime. In fact, the researchers claim that there is a connection between JFK’s assassination, Watergate, and the Iran-Contra scandal, in which George H. W. Bush played a part. Some believe that Bush Senior was responsible for John Kennedy Junior's death as well based on speculation that John Junior was about to reveal the truth about his father's assassination.

6. The Illuminati Theory

In this version of events, the Reserve Bank is again implicated, but this time it’s because they served the Illuminati Agenda. Once more, Executive Order 11110’s supposed lessening of the Reserve Bank’s powers is cited as the reason behind the assassination. JFK’s intention to stop the war in Vietnam is also put forward as a factor, as the conflict allegedly added vast amounts of $$$$$$$$ to the shadowy bankers’ coffers.

An interesting side note is that Kennedy himself was part of the Illuminati – if this theory isto be believed. They accuse JFK’s father, Joe Kennedy, of being in bed with the Mob, an Illuminati supporter, and part of the so-called “Illuminati Bloodline”. In fact, they say it was his association with the secret organization that got President Kennedy elected in the first place – and it was only when he turn against them that they had him eliminated.

7. The KGB Theory

The CIA had Cold War rival was the KGB. The KGB had good reason to hate Kennedy after the humiliating ending to the 1962 Cuban Missile Crisis. Sniper Lee Harvey Oswald also had links with the USSR like his USSR travels, his Soviet wife, and his reported contact with Soviet diplomats. Some researchers also believe that the KGB were responsible for the death of one of JFK’s alleged mistresses, Mary Pinchot Meyer, who could have exposed the KGB role in the assassination.

One version of the story, as told by ex-Soviet intelligence officer General Ion Mihai Pacepa, is that Lee Harvey Oswald was a KGB agent “programmed” to kill President Kennedy. According to Pacepa, the KGB actually tried to call off the assassination; unfortunately for JFK, however, the attempt to stop Oswald came too late. There is factual evidence to back up this theory.

8. The Israeli Theory

“It is interesting – but not surprising – to note that in all the words written and uttered about the Kennedy assassination, Israel's intelligence agency, the Mossad, has never been mentioned,” said Illinois Representative Paul Findley, in the 1992 Washington Report on Middle Eastern Affairs. Why has one of the most efficient and ruthless intelligence organizations in the world never been scrutinized?

Israel’s motive for eliminating JFK was because Kennedy refused to allow them to build nuclear weapons. It’s been said that David Ben-Gurion, the Israeli Prime Minister at the time, held a grudge against President Kennedy’s father, Joe. Ben-Gurion believed Joe Kennedy was anti-Semitic and suspected that he had sided with Hitler during the ‘30s and ‘40s.

This conspiracy theory has also been bolstered by ex-Israeli spy Mordechai Vanunu, who has said that Israel was behind the JFK assassination. Supporters of this hypothesis also point to subsequent US President Lyndon B. Johnson. Johnson’s reversal of the nuclear policy is seen as a sign that Kennedy’s assassination achieved its aim. Perhaps unsurprisingly, Gaddafi was a well-known promoter of the Israeli-involvement theory.

9. Gay Thrill Kill Theory

President Kennedy was assassinated for the fun of it, according to Jim Garrison, who was the New Orleans District Attorney at the time. “It was a homosexual thrill-killing, plus the excitement of getting away with a perfect crime,” said Garrison.

In Garrison’s view, many, if not all of the conspirators behind the killing of Kennedy were homosexual deviants who took pleasure in plotting the President’s death. Understandably, there are few who take this charge seriously.

10. The CIA Theory

Whether it was Lyndon B. Johnson, The Federal Reserve, the Mafia, the KGB or an attempt to cover up evidence of UFOs, the CIA is seen as an important player.

The fact that President Kennedy’s brother Robert effectively had authority over the CIA didn’t help when it came to strong disagreements between the President and the agency. And strangely enough, one of the disagreements was over the CIA’s policy of assassinating foreign leaders, such as Vietnam’s President Diem.

Such is the popularity of, and belief in, this conspiracy theory that the CIA has a page dedicated to discrediting it on their website. They blame European leftists and the US media for spreading lies about their involvement. Yet despite this, widespread acceptance of the theory continues.